DC3

According the previous owner, the '73 I recently acquired does not have the original small block motor. He said his engine builder told him the current block came out of a Chevelle but he wasn't sure it was even the original motor for the Chevelle. He also said it was supposed to be a 4-bolt main block.

Here are the numbers I could find on the block:

Found on the drivers side rear near the firewall facing up and reading left to right from the drivers side:
25 GM
3970010
(the "25" is turned 90 degrees clockwise and so is readable from the drivers side fender)


Found on the passenger side near the firewall under the distributor and also reading left to right from the drivers side:
F 6 3
There's a little space between each of these but nothing else apparent in between.

Found stamped on the front passenger side pad:
CE3A57 4 1
The C and E are very hard to read. The C could be an O or 0. The E could be an F. I suppose the A could also be a 4 but it doesn't look like the next 4. The last 4 and 1 are not near and don't line up with the other numbers and are also not beside each other and don't line up with each other.

I also found some markings on the block under the distributor on the drivers side:
1. There is a circle of 10 raised dots with a tear shaped pointer pointing at one of the dots and somewhat toward the front of the engine. The third dot clockwise from the one being pointed at has a second dot beside it just outside the circle.
2. Near the above circle of dots is three letters arranged in a circle 120 degrees apart. There is a "T", a "D", and an "N". There is a tear shaped pointer pointing at the N.

There is no pad and no numbers on the drivers side front of the engine block.

So, what do I have?

DC

Artsvette73

From what I know a CE block is a service replacement. The 010 is a 350. Someone else can help you with the other numbers you provided as to the year.

hgm

Try this link http://www.mortec.com/
It will help with block identification

DC3

Thanks. From this site I was able to determine that 3970010 is either a 302, a 327, or a 350. It looks like F63 is the block casting date which means June 6, 1973 and therefore confirms the block is a 350 as Artsvette73 has already said.

The Mortec site didn't help with the other numbers.

I was able to find some info on another website that said the circle of dots is a "casting clock" and probably means the block was made in the Saginaw plant. There are 10 dots because of the 10 hour work shifts. The pointer points to the beginning of the shift and the extra dot outside the circle is the hour the block was cast. So, if I'm interpreting that correctly, it means my block was cast in hour 4 of the workday of June 6, 1973.

That leaves the "25" and the T, D, N circle to explain. I would also like to know if it is possible to decode the CE number on the passenger side front pad.

DC

DC3

Bump

400hp427vette

ce means an over the counter gm crate engine also used for warranty replacements which would be a gm crate engine ordered aswell

DC3

I received a PM from karol with a link (http://www.nastyz28.com/chevy-engine-code-stampings.php) to a website confirming your description of CE. Is there anyway to decode the numbers after the CE?

DC

400hp427vette

Nothing I know of, Call gm they should have an idea

lr172

I have a CE bloack as well (512). To my knowledge, the first digit is the year built and the rest is just an engine serial number.

DC3

Thanks. That makes sense as the first number after the CE is a 3 which corresponds to the date code.

That leaves the "25" and the T, D, N circle to explain. Anyone?

Any easy way to determine if this is indeed a 4-bolt main block?

DC

jackson

you have a CE block.

No ... AFAIK, there is no way to KNOW whether 2 or 4bm ... without pulling pan & looking at caps. AKAIK, all the decoding & chasing numbers ain't gonna tell you.

DC3

That's kinda what I figured. No big deal but someone told me he thought there was a way to identify some older 4 bolt main blocks depending on where they were built but he couldn't remember how.

I guess the "25" and the T, D, N circle has everyone stumped?

DC

PatsLs1vette

yes i know what its for --its for when it was made --day or night shift yours is night shift.,and if theres a circle of dots and its pointing to one of them thats the time it was built.HOpe that helps.
one other thing to the circle of dots and arrow pointing to the dot is when the shift started the double dot is the time it was cast.

DC3

Hey, thanks! I had already figured out the circle of dots. See one of my earlier posts. But you've now clarified that it was hour 4 of the night shift.

So, you are saying the N references night shift and the D references day shift? Then what does the T mean?

I guess the story of my engine begins with "It was a dark and stormy night".

DC